1. Field of the Invention
The present invention relates to a water pump attachment structure of a water-cooled internal combustion engine.
2. Description of Background Art
A water-cooled internal combustion engine is known wherein a valve train having a camshaft disposed on a cylinder head is provided so as to be covered by a cylinder head cover. This internal combustion engine is configured as described below. A water pump housing for a water pump is provided across the cylinder head and cylinder head cover. In addition, a pump drive shaft rotatably supported in the water pump housing is disposed coaxially with a camshaft and rotated in conjunction with the rotation of the camshaft. See, for example, Japanese Patent No. 3,963,532.
Japanese Patent No. 3,963,532 discloses a water pump housing that is provided across the cylinder head and the cylinder head cover is attached to and supported by both the cylinder head and the cylinder head cover by means of bolts.
When the maintenance of the valve train such as adjustment of a tappet clearance is carried out, to remove the cylinder head cover, the water pump housing for the water pump has to be first removed from the cylinder head and the cylinder head cover. More specifically, work has to be done from a plurality of lateral sides of the engine, which makes the maintenance work cumbersome.